Polysiloxanes, especially silicone rubber, find use in a wide range of technical and medical fields. Silicone rubber has a high oxygen permeability, for which reason the material would be expected to be suitable for the manufacture of contact lenses. However, silicone rubber is a hydrophobic material, and for this reason this material cannot yet, because of resulting problems, be used for this purpose although it has been suggested, since about 1960, to make the material suitable for contact lenses. At the present time two differing methods have been tried in order to make silicone rubber usable for this purpose. One method consists of rendering the silicone rubber surface hydrophilic (European Pat. No. 0,033,754, U.S. Pat. No. 4,143,949, French Pat. No. 2,407,232, German Auslegesschrift Nos. 2,353,495 and 2,164,805). Another known method (U.S. Pat. No. 3,925,138) consists in putting polar groups into the polymer chain.
It is an object of this invention to provide a modified silicone rubber which is hydrophilic, and to provide a process for its synthesis.